This invention relates generally to the catheterized treatment of a stenosis or blockage in a bodily passageway such as an artery or the like, and more particularly the invention concerns an apparatus and method for determining the optimal placement of the catheter in the bodily passageway for treating the stenosis. The invention also relates generally to an apparatus and method for creating holes or channels in a hyproperfused area of a heart with a catheter tip energized by radio-frequency waves.
A stenosis is a narrowing or constriction in a bodily passageway such as an artery. One such type of stenosis is known as atherosclerosis and occurs in blood-conveying arteries in humans. Heretofore there have been a variety of apparatuses and methods for treating such stenoses, such as mechanical, ultrasound and laser apparatuses and methods. All of these apparatuses and methods have in mind the ultimate goal of treating a stenosis so that it does not reoccur. The ultimate goal of these treatments is to unblock the stenosis so that it does not return so that a patient who suffers from such condition may go on to lead a normal life.
The apparatuses and methods in the prior art have largely failed to achieve this goal because up until now, discovering the optimal placement of a catheter in a bodily passageway to achieve the most efficient heating of a stenosis has not been available. While the prior art apparatuses and methods have failed to determine the optimal placement of a catheter in an occluded passageway, the present invention has succeeded in providing an improved device and method which reduces the chances of restenosis or a reoccurrence of the stenosis.
A problem related to the stenoses in coronary arteries manifests as a hypoperfusion, or below normal blood flow, in one or more areas of the heart muscle, which are detectable by thallium scintigraphy. Lasers have been used to treat such hyproperfused areas of the heart by lasing the endocardial surface of the heart, for example in the left ventricle, to create small holes or channels part-way through the heart muscle, roughly perpendicular to the surface. The subsequent healing of the heart in the area of the channels is believed to involve the angiogenesis of small blood vessels, resulting in an increase in perfusion of the area. However, lasers designed for this technique are expensive, and the associated catheters are stiff and have an outer diameter that creates a risk of unwanted damage to the heart and blood vessels. Additionally, the catheters include a fiberoptic laser delivery device and are expensive, and can usually be used only one time.
With the above problems in mind, it is an object of the present invention to provide an apparatus and method for the treatment of a stenosis which reduces the chances of a reoccurrence.
It is another object of the present invention to provide an apparatus and method for locating the optimal position in a bodily passageway for the treatment of a stenosis.
It is yet another object of the invention to provide a catheter for use in treating a stenosis which uses radio frequency energy to capacitatively heat the same.
It is a further object of the invention to provide a catheter and a controller for delivering radio frequency energy to the catheter, in which the controller includes a system for determining the optimal placement of the catheter in the bodily passageway.